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Coffee Preparation

FOUR ESSENTIALS FOR GOOD COFFEE

Anyone wanting to make a good espresso has to meet four essential needs. The first is the choice of the right blend, the second is a proper espresso machine – properly maintained, the third is the right grade of grind and the fourth is the knack with which the measure of coffee is tamped. Espresso must be easy on the eye (with froth – also known as crema – which is thick and nutty-red in colour), the nose (with a rich aroma) and the palate (almost chocolatey). And of course it has to leave a pleasant taste in the mouth for a good long time after being drunk (after-taste).

The machine should be carefully looked after to make sure that the water temperature is correct, the water has the right degree of hardness and the parts are clean. The nozzle for frothing the milk should be cleaned every time it is used and the filters, filter holders and dispenser groups washed at the end of every day – and no detergent please!

The degree of the grind should be carefully adjusted on the grinder. Coffee is highly sensitive to humidity – in dry weather the grind needs to be a fine one, while damp or rainy conditions require a coarser grind. An espresso measure is between 6.5 and 7 grammes. The grinder should be cleaned regularly, especially the bell containing the beans.
In addition to bearing the above points in mind, you should press the measure of coffee so as to distribute it evenly. A good espresso will pour down in an unbroken walnut-coloured stream for about 10-15 seconds per cup. The result is a total of 30-35 ml of coffee in a pre-heated ceramic cup.

THIS IS HOW TO MEASURE IF THE CORRECT BALANCE HAS BEEN ACHIEVED

Once you have dispensed the correct amount of ground coffee in the portafilter basket ( that should never be less then 8 gr p/person ), tamp the coffee down with the tamper and re attach to the brew head. switch on the pump and you should not see any coffee coming out of the porta filter before a 4-5 sec delay, if the coffee exits sooner then the grind is too coarse, adjust setting and proceed with another test cup. The same applies if the cofffe only exits much later then 4-5 sec, the grind is too fine, adjust and proceed with a further test cup.

If your machine has a pressure gauge and it exeeds 10-11 bar then the grind is too fine, the reverse is the case if the gauge reads below 10 bar. Again adjust your grinder and test again.

On a lever machine your grind should be quiete fine and use a very light tamp, as the lever is activateted you need to wait until the coffee begins to drip from the porta filter before commencing the extraction process.

ADVICE FOR AN OPTIMUM ESPRESSO

An espresso can be judged by a simple look. An optimum espresso looks good – thick and lasting cream with the sugar sinking slowly through, an inviting dark nutty colour with reddish highlights and slight streaks. This optimum result is not easy to achieve. Many variables can lead to a negative outcome – an inadequate blend, improper maintenance and use of the equipment (espresso machine and/or grinder-dispenser), wrong grinding setting, coffee left to oxidise in the air for too long.

The two most common defects in an espresso are underextraction and overextraction. As may be understood from the term, in the former case the components needed for a balanced coffee are not sufficiently extracted, and in the latter in which too much is extracted, but the result is no better for that. To judge the correct time delay at the beginning of the extraction process one should achieve a 4-5 sec delay before any coffee emerges from the portafilter after switching on the pump.

The results in the cup can be predicted as soon as the coffee begins to emerge from the spout of the espresso machine. Underextracted coffee pours out very quickly, in less than the prescribed 15 seconds, in a continuous non-creamy jet. The coffee will have a light-coloured, almost whitish, cream of low density. Overextracted espresso will pour out slowly, drop by drop, taking more than the standard time. Its cream will be dark, of low density and short duration.
These two defects can have a number of causes. Here is an analysis of some of them, along with the best ways to remedy them.

UNDEREXTRACTED ESPRESSO

The measure of coffee is insufficient. From a kilo of coffee 100 espressos should be extracted, at a weight of 8-9 grammes per measure ( that is one espresso ). A measure weighing less than 6 grammes is likely to result in an underextracted espresso. Check the weight of the measure and increase it to the standard if necessary.
The grind is too coarse. The water passes through the coffee powder too quickly, simply washing it without extracting the aromas and flavours. Coffee absorbs humidity from the environment, so the grind should be adjusted daily according to atmospheric conditions – a finer grind in dry weather, a coarser grind in damp weather.
The measure is not tamped hard enough. A measure of coffee should always be tamped when placed in the machine. This gives an even distribution of the powder and makes sure that the water passes through all of it. The measure can be tamped with a special tool or using the shaped part of the grinder-measurer.
The temperature of the water in the espresso machine is less than 90°C. In this case the water has less strength to separate the aromas and flavours from the coffee powder and carry them to the cup. The boiler pressure should be increased to take the water to the required temperature.
The pressure in the pump of the espresso machine is more than 9 atmospheres. The water is forced through the coffee too quickly and the extraction time is too short. The pump pressure should be reduced.
The machine is not properly cleaned. If the spouts are blocked the water is not distributed evenly and part of the measure of coffee goes to waste. The spouts should be cleaned with the blind filter, as indicated in the instructions.
The holes in the filter have increased in size. This also means that the water passes through the coffee too quickly, which leads to underextraction. Filters should be checked regularly and replaced when necessary.

OVEREXTRACTED ESPRESSO

The factors leading to overextraction are similar to those causing underextraction, and the same goes for the remedies.
The measure of coffee is greater than is necessary. It should be weighed and reduced, if necessary, to the standard of 7-9 grammes.
The grind may be too fine. When wet the powder tends to form a kind of mud that slows down the passage of water through the coffee. In this case a coarser grind should be used.
The coffee has been tamped too hard. The coffee powder is too compact to allow the water to pass through normally. Take care to press more lightly. This is also manifested by only one spout delivering coffee initially.
The temperature of the water in the machine is too high (above 95°C). Reduce the pressure in the boiler.
The pump pressure is less than 9 atmospheres. Adjust it to the proper level ( by adjusting the grinder and tamping correct )
The spouts are blocked. As in the case of underextracted coffee, they should be cleaned with a blind filter and back flushed, this is very important to maintain the selonoid valve function at the optimum.
The filters and filter carriers are blocked. Here too, the sensitive parts of the machine should be carefully cleaned.

A bad coffee may be the result of several causes acting together. A daily check on the cleanliness of the various components and proper coffee management (appropriate degree of grinding and a quantity of ground coffee no greater than immediate needs) are of basic importance for the preparation of a good espresso. A good espresso cannot be obtained from a bad blend, but if proper care and attention are not used during preparation an excellent blend can produce a disappointing cup of coffee.

The important of cup sizes for Coffee

Stronger? Weaker? How would you like your coffee?
Many people do not realize that the size of the cup is probably one of the most important factors for good flavoured coffees. A smaller cup size (5 – 8 oz) usually results in a flavourful caffe latte or cappuccino.
Speed is an important issue in a commercial environment and we therefore mainly use a single or double espresso. That said, there are places that have triple group handles. A 6 oz cup with a single shot of espresso will taste very different than a 12 oz cup with a single shot of espresso. A smaller cup will do the espresso more justice and it will be much quicker to make. Smaller caffe lattes or cappuccino’s will also be healthier for your customers.
Big cups will have the tendency to taste more like hot coffee flavoured milk. A caffe latte or cappuccino should really taste like a good balance between milk and espresso. This means that large cups make it very hard for the espresso to punge through all that milk.
And do not forget that your large coffee should be twice the size as your regular.
Consider your cup sizes and really do try different cups. It is not for no reason that we use 5.5 oz cups for cappuccino’s in the Barista Competitions.